Manufacture of fiber-board.



WITNESSES T. MALCOLM.

MANUFACTURE OF FIBER BOARD.

APPLICATION FILED JULY 2,1907.

Patented Dec. 8, 1908.

G INVENTOR. If Malcalm,

BY/W' A TTORNE Y.

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a esthesia ()FFICE.

THOMAS MALCOLM, or HARTFORD, CONNECTICUT, ASSlGNOR TO JOHN rREeomNo, or

HARTFORD, CONNECTICUT.

' new and useful Improvements in the Manufacture of Fiber-Board, of which the following is a full, clear, and exact specification.

This invention relates to the art of manufacturing sheets of fibrous substances, and

more especially to the manufacture of what is generally known" as leather board, and it has for one of its objects the'production of such board the fibers of which are thoroughly knit together and compressed, this knitting together or intermingling being the result of constant agitation during the coinprcssion of the pulp mass, as for instance by a machine and a method shown,described, and claimed in a contemporaneously-pend ing application-for Letters Patent, filed by me on May 18,1907, under Serial Number 374,939, and to which reference maybe bad.

My invention has, furthermore, for its object the provision of a fiber-board embodying a resilient or flexible reinforcing medium which consists substantially of a sheet of open-texture fabric or a wire-netting,

through the meshes ofwhich the fibers of the pulp pass and interiningle at opposite sides thereof,.thus produclng an article which possesses materially-increased tensile strength, can be very cheaply made, and has all the qualities of density of the best tanned and seasoned leather; while, on the other hand, the pulp or fiber-sheet can readily be molded into; any desired shape or form, suchas pails, vessels, dress-suit cases, trunks, etc.

In order to give a clear understanding of the present invention, I have shown in the drawings a machine in which my improved fiber-board may be economically manufactured, the particular method of forming such board being of importance as far as the product is concerned,Figureil being a central vertical section of such a machine. Fig. 2 represents a top view of a plain sheet of my improved fiberboard, some portions being broken away to disclose others, and Fig. 3 shows a section through the sheet.

Referring to the drawing, the numeral 10 denotes the base or stand of the machine provided at its top with a plate 11, having aper- Specification of Letters Patent. Application filed. July 2, 1907. Serial No. 381,947

Patented Dec. 8, 1908.

tures l2 and carrying on'its upper face a molding box 13 which may he of any suitable shape and be secured to the plate 11 in any desired manner. Disposed for movement and closely fitting in said box 13, is aplunger, preferably made in two parts and comprising the bottom plate 15 and top casing 16 so as to leave achamber li which is in communication with; apertures 18 in the plate 15. Disposed ontop of the'base plate 11 is a screen 20 consisting preferably of a foraminated sheet p,lat'e, the apertures of which are comparativelyffine so as to permit the water in the pulpf'to escape therev-from and yet retain the pulp fibers within :the molding box The plunger casing 16 is attached to the lower end 01%, aapiston rod 25 having at its upper end a piston 26 mow able in a cylinder 27, and operable therein three-way valve 30 'of ordinary construction. Secured to the underside of plungerr iilate 15 is a foraminated plate 32 having a series of fine apertures registeringwith the somewhat larger openings 18 of the plate above mentioned. v

In using the machine for compressing the leather pulp which consists principally of scrap leather reduced to the required. fineness, and water, the plunger is first raised out of the molding box 13, and a thin layer of pulp is then laid on top of the fol-amt nated plate 20. On top of this pulp layer I place the reinforcing member, consisting of a sheet of open-mesh textile fabric or fine wire netting or gauze Gr, and then another layer Off pulp is laid on top of said gauze-sheet. The plunger is then lowered into the molding box, and a current of air under high pressure is sent through the mass. This action will naturally result in driving the fibers of the upper pulp layer through the interstices in the ganzesheet and cause them to intermingle and knit together with those of the lower pulp layer, while at the same time the water in the pulp will be forced through. the foraminated plate 20, the apertures 12 in the plate 11,

and then into the chamber- 4:0 of the "base' l0. I This chamber std-has a-bottomphite 4:11pmvided with a discharge-conduit 42 through which the waste water may, be-withdrawnfrom the chamber 4 0,,th'bonduit42 being connected with a waste-pi cs3 which may be closed by a valved-i, an also with a pipe 45 leading to a suction pump (not shown) and adapted to be'closed by a valve 46. The chamber 40 is also connected with the pressure supply above mentioned, by av pipe 47,

Air under pressure may be introduced into the plunger casing 16 by apipe 50 provided with a valve 51, and said casing. is also con-- nected with the. waste-pipe, and with the suction pump, by pipes 52, 53, respectively,

having valves '54, 55. By virtue of the several valves above mentioned, I am enabled to meet almost any CODdIlLIOH, required to produce a board the fibers of which are thoroughly interwoven and knit together, and which has been completely-relieved "from moisture without the. aid of heat, so that the liability of the finished board to warp,

will be minimized.

As above stated the pulp-mass is malntained in agitation during the, compressing Q30; 1 By now1closin.g the waste-valve 44,.andopenprocess-byair under pressure, in which case the air-valve 51 vand waste-valve-ta are open.

ing the suction-valve46, I am enabled to increase the eificiency of the air blast through the,

'- pulp'to any desired degree within. thecapacity of the machine. Byclosingthe air valve 51, suction valvesffihgiand wastesvalve 44,

and thenopening suetionev alve 55fand lower air valve 3 .8, the" directionof the l air; current.

passing through the pulp-mass will be reversed, and the moisture will be ejected from the upper-portion of the pulpfwithout passing through the body thereof.. Ina-manner similarto that above-stated,the efiiciency of the upward air-current maybe increased .by closing the waste-valve 54, and opening the suction-valve 55.

It may be stated that the medium employed for actuating the'plunger When com-; pressing the pulp in themold-box, may be in the nature of any highpressure fluid, and,

inasmuch as the movement of the plunger should necessarily be comparatively slow, 111 order to permitthe air-current to agitate the fibers of the pulp mass and at the same time exclude the moisture therefrom, it may be advantageous to operatesaid plunger under a hydraulic system so as to Obiitlll the required plunger speed, and also the high pressure necessary to perform the work.

.l rom the foregoing it will be understood that, when leather is tobe employed for the formation of the board, scraps may be used,

these" scraps being shredded rather than ground, so as not xto destroy the fibrousv qualities. .Also insteadof forming-the pulp-mass by adding water to the leather, any suitable sizing or .cementing mixture, either v plain or water-proof, may. used accordin to the purposes for, which the finished H gr not is intended, theprincipal'featureof t e present invention residing -in;the fact; that the fibers of the pulp are really crossed and re crossed among theinselves, of simply compressed wlnle in a dormant: CODdItlOIL.

The intimate,.not to say homogeneous-quality and coherence of the fibers, is. naturally due .to the constant agitation by air-currents forced througl1 the mass andiconsequently .crowdingjthe' fibers in all directions so that a thorough intermingling results.

Under some circumstances, as forinstance when forming vessels, pails, dress-suit cases, trunks, or similar articles of a predeter mined or fixed shape, the reinforcing medium maybe of a stifi". nature, so that the latter me) be instrumental in preserving the original s apeof the article, without relying; uponthe strengthof the pulp to sustain the;

same, so that in such an instance the density ofithe pulpv and its imperviousness to mo1s-,

ture only are taken advantage ofto render such vessel water-tight.

am aware that fiber-board reinforced by wire-netting has been made and patented,

and .I do not lay'any claim to a-fiber board in which the layers of fiber pulp: placed-on each other or from the sides of th netting. V I. clai fr improved articleof manufacture, a

leather-board consistingnf fibrous material having 'embeddeditherein a sheet of, wire gauze','the' fibers passing: through the meshes v of the gauze and being interlaced at the opposite sides th i v I THOMAS MALCOLM. Witnessesi 4 CHAS. F. SGHMELZ, A. F; BUR-Ne.

Correction in Letters Patent No. 906,044.

- It is hereby certified that Letters Patent No. 906,0t-l, granted December 8, 1908, upon the application of Thomas Malcolm, of Hartford, Connecticut, for an improvement in the Manufacture of Fiber-Board, were erroneously issued to John Tregoning, as owner of the entire interest in said invention; whereas sairl Letters Patent shouldhave been issued to the inventor Thomas Malcolm and John Tregoning, jointly, said John Tregoning being the assignee of part interest only in said patent, as shown by the record of assignments in this oflice; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice. Signed and sealed this 19th day of January, A. 1)., 1909.

[SEAL] o. o. BILLINGS,

Acting Commissioner of Patents. 

